Put the Tamarind Pulp (3/4 cup) in a bowl and top it with hot water.
In a deep sauce pan on medium heat, pour in Olive Oil (1 tablespoon) then add the large onion. Turn heat down to low and let this slowly cook for 5 minutes, stiring often.
Add Salt (1/2 teaspoon), Fresh Ginger (1 tablespoon), Ground Allspice (1/2 teaspoon) and Ground Black Pepper (1/2 teaspoon) and toast the spices for a minute. Make sure to stir so the spices don't burn.
Add Onion (1), Scotch Bonnet Pepper (1), Worcestershire Sauce (1/4 cup), Ketchup (2 cup), Molasses (2 tablespoon), Brown Sugar (1/4 cup), Apple Cider Vinegar (1/4 cup) and Yellow Mustard (2 tablespoon) into the pot. Raise to medium heat, stirring often.
Using a fork, break up the tamarind pulp, then massage it with your fingers. Discard as much solid (seeds and fibers) as you can. Strain the liquid into the pot. Stir well.
Turn the heat back up so you get this back to boiling, then turn the heat down to a very gentle simmer for 30-45 minutes.
Use this sauce for grilling, a dipping sauce for your chicken fingers or for burgers. Store in glass containers in the fridge and it will remain good for at least a couple months. Enjoy!